Fuse



J. H. HICKEY Feb. 26, 1929.

.FUSE

Filed Oct. 25. 1926 Patented Feb. 26, 1929.

UNITED STATES JOHN H. HICKEY, OF SAN FRANCISCO, CALIFORNIA.

FUSE.

Application led October 25, 1926.

My invention relates to improvements in fuses, and particularly toimprovements in fuse construction whereby a fusible conductor is vmadereadily replaceable and is rendered observable in service.

The primary object of the present invention is to provide improvedconstruction for fuses.

Another object is lto provide an improved fuse wherein the fusibleelement is normally completely encased within an insulating shell and inwhich the fusible element may be rendered observable when desired.

A further object is to provide improved means for detachably mountingand connecting the fuse terminals upon the body ofthe fuse to facilitatethe initial assembly and the subsequent refilling of the fuse.

A further ob] ect is to provide an improved means for detachablymounting thc fuse terminals which will obtain maximum conductiveefficiency.

Another object is to provide an improved construction which willfacilitate the connecting of a fusible conductor between the terminalsof a fuse and which will obtain full conductive efficiency.

A still further object is to provide an improved fuse construction whichcan be manufactured economically and which will be highly efficient bothelectrically and mechanically.

I accomplish these and other objects by means of the improved devicedisclosed in the drawings forming a part of the present applicationwherein like characters of reference are used to designate similarpart-s throughout the specification and drawings and in which,

Fig. 1 is a side elevation, partly in section, ofv my improved fuseconstruction.

Fig. 2 is a longitudinal section taken at right angles to the fuse asshown in Fig. 1.

Figs. 3 and 4 are transverse sections taken upon the line 3 4 of Fig. 1,showing the cover moved to cover and to uncover respectively theopenings in the shell.

Fig. 5 is a side elevation, partly in section, of a smaller type offuse, showing the adaption of my improved construction thereto.

Fig. 6 is an end elevation of the fuse shown in Fig. 5.

Fig. 7 is a broken sectional detail showing the manner in which theconductor caps are locked upon the ends of the shell.

Serial No. 144,008.

Referring to the drawings, the numeral 1 1s used to designate a shellhaving openings 2 formed in the sides thereof. Conductor caps 3 aredetachably mounted upon the shell, said caps being fitted over the endsof the shell and detachably secured against rotative movement thereon bymeans of screws 4 threaded into the sides of the shell 1 and engaginglongitudinally disposed slots 6 formed 1n the edges of the caps 3. Lugs7 are upwardly turned at the outer ends of the slots 6 to engage theheads S of the screws 4 to lock the caps against longitudinal movementupon the shell. The screws 4 are arranged to be loosened sufficiently topermit the heads 8 to clear the lugs 7 whereby the caps may be moved offfrom the shell when desired without entirely removing the screws fromengagement with the shell 1.

Terminals 9 are detachably secured upon the conductor caps 3. Theterminals 9 are provided with shank portions 11 extending axiallythrough the cap and contact lugs 12 extending inwardly into the shell.The shank portions 11 are preferably made rectangular in form and extendinto recesses 13 formed in the backs of blades 14 secured upon the outerends 0f the caps and arranged to engage a fuse block, not shown, in theordinary manner. A lug 16 is formed upon each cap at the base and inconnection with one side of the corresponding blade 14, said lug beingarranged to engage and form conductive contact with one side of theshank. A clamping block 17 is mounted adjacent the opposite side of theshank, said block being arranged to be clamped against the shank bymeans of screws 18 threaded into the blade 14 and lug 16, whereby theshank may be detachably clamped between the block 17 and the lug 16 andform an eficient conductive contact.

The contact lug portions 12 extend inwardly from the caps 3 into spacedrelation Within the shell and are arranged to receive the ends of afusible conductor 19 of predetermined current carrying capacityextending therebetween. The conductor 19 has a. slot 21 formed at eachend to receive a screw 22 threaded into the lug portion 12 and arrangedto move a. clamping block 23 into firm contact-ing relation with the endof the conductor 19 whereby the fusible conductor may be detachablyclamped and an eflicient electric contact maintained. The fusibleelement 19 may be of any desired character, a

form in which the element is apertured to form a conductive grid ofknown current car rying capacity being illustrated.

A cover 24 is mounted over the shell 1 between the caps 3, said coverhaving openings 26 formed therein to substantially correspond to theopenings 2 formed in the shell 1. The cover is arranged to normallycover the openings 2 and is movable to move the openings 26 intoregistering relation with the openings 2 whereby the fusible element 19within the'shell may be observed. A transparent pane 27 of glass orother suitable material is preferal'ily mitered into the openings of thecover 24 to insure that the fuse will be housed entirely should thecover be left inadvertently or intentionally w"h the open` ings 26 inregistering relation with the openings 2. A screw 28 mounted upon theshell 1 and engaging a slot 29 formed in the cover 24 limits themovement of the cover 2a relative to the shell 1.

In assembling the fuse, the screws 22 and 18 are readily tightened toobtain a rigid clamping of the terminal of the fusible element 19 andthe caps 3 respectively, and the flat contacting surfaces are caused tomaintain an efficient conductivity. The screws 4 efliciently hold thecaps against longitudinal and transverse movement, so that no strainwill be imposed upon the fusible conductor 19, and said conductor willbe held at all times in a position such that it may be readily observedthrough the registering openings 2 and 26.

The shell 1 and cover 24 are lpreferably made of insulating material andthe cover is preferably held with the openings 26 and 2 out ofregistering relation, thereby obtaining a continuous insulating casingaround the fuse. l/Vhen it is desired to locate a fuse that has beenblown, the cover of each fuse has only to be turned sufficiently to movethe openings 26 into registering relation with the Openings Qrof theshell and the fusible element may then be observed without removing thefuse from' the block, In this manner the locating of blown fuses isgreatly facilitated. f

In replacing a blown fusible element 19, the screws 4 are loosened topermit the caps 3 to be removed from the shell 1, and the screws 18 and22 unloosened sufficiently to rele-ase Ythe clamping blocksV fromclamping positions. It will be noted that none of the screws needbeentirely removed, hence, there is no danger of losing any of said screwsand thereby destroying the utility of the fuse.

In smaller fuses, such as illustrated, in Figs. 5 and 6 of the drawings,the terminal elements 9 may be eliminated. In fuses of this smallertype, the shell 1 and cover 2e are arranged as above described, and conductor caps 3 arranged to engage fuse blocks directly, are secured uponthe shell in the mannerl above described. In this form of fuse, thefusible element 19 consists of a suitable length of fusible metal ofcalculated current carrying capacity, the ends of said element beingextended through openings formed in the ends of the caps 3. A lug 16 isYformed upon the outer end of each cap, and a clamping block 17 isconnected to said lug bymeans of screws 18, said block being movable bysaid screws to firmly clamp the ends of the fusible conductor and tomaintain an eliieient electrical Contact therewith. The fusible elementis easily replaced in this type of fuse by removing the cap andloosening the clamping block screws 18( in the obvious manner. Y e

My improved fuse, and the structural features particularly described inthe present specification are, of course, subject to modilieation innumerous ways without departing from the spirit of the invention. I,therefore, do not wish to restrict myself to the specific form andconstruction illustrated and described, but desire to avail myself ofall modifications which may fall within the scope of the appendedclaims.

Having thus described my invention what I' claim as new and desire tosecure by Letters Patent is 1. A fuse comprising a shell; conductor capsmounted upon the ends of the shell, said caps having longitudinallydisposed slots formed in the inner edges thereof and provided withoutwardly turned lugs formed adjacent the ends of the slots; screwsmounted upon the shell and engaging the slots to hold the caps againstrotative movement, said screws being provided with heads engaging thelugs to secure the caps against longitudinal movement; a' fusibleconductor; and means for detachably connecting the conductor between thecaps within the shell.

2. In a fuse, the combination with a shell and conductor caps arrangedto fit uponA the ends of the shell, of a screw mounted within the shelladjacent each cap and arranged to slidably engage slots formed in theedges of said caps to hold the caps againstrotative movement; and lugsoutwardly turned from the outer ends of the slots to engage heads formedupon the screws to hold the caps against longitudinal movement. Y Y

3. In a fuse, the combination with a shell and conductor caps detachablysecured upon the ends thereof, of a pair of terminals detaehablyengaging the caps, said terminals having shanls extendingaxially throughthe caps; lugs formed upon the outer ends of the caps to engage one sideof each terminal; and

yblocks arranged to befclamped against the opposite sides of theterminals to detachably clamp the Shanks into conductive contactwith thecap. Y n

4. In a fuse, the combination with al vshell ,andV conductor capsdetachably secured uponv the ends thereof, of a pair of terminalsdetachably engaging the caps, said terminals having shanks extendingaxially through the caps; lugs formed upon the outer ends of the caps toengage one side of each terminal; and blocks arranged to be clampedagainst the opposite sides of the terminals to detachably clamp theShanks into conductive Contact with the cap; terminal lugs formed uponthe inner ends of the terminals; and blocks movably connected to theterminal lugs and movable to clamp a fusible conductor into detachableconnection therebetween.

5. In a fuse, the combination with a shell and conductor caps detachablysecured upon the ends thereof, said caps being provided With cont-actblades arranged to engage a fuse block, of a pair of terminalsdetachably engaging the caps, said terminals having rectangular Shanksextending through the caps and into recesses formed Within the backportions of the blades; lugs formed upon each cap in connection with oneside of the blade to engage one side of the shank; and a clamping blockconnected to the opposite side of the blade and movable to clamp theshank into engagement with the cap and shank, said block forming flatconductive Contact With the shank. i

6. In a fuse, the combination With a shell and a conductor capdetachably secured upon an end thereof, of a terminal detachablyengaging the cap and having a .sha-nk extending axially through saidcap; a clamping lug formed upon the outer end of the cap to engage oneside of the shank; and a clamping block arranged to engage the oppositeside of the lshank to detachably clamp the terminal in conductivecontact with the cap.

nature.

JOHN H. HICKEY.

